gnb: improve cgroup management

lib/support/sysinfo.cpp

@@ -27,9 +27,21 @@ static bool exec_system_command(const std::string& command, const std::string& c
   return true;
 }
 
+/// Writing the value 0 to a cgroup.procs file causes the writing process to be moved to the corresponding cgroup.
+static void move_to_cgroup(const std::string& cgroup_path)
+{
+  std::ofstream output(cgroup_path + "/cgroup.procs");
+  if (output.fail()) {
+    fmt::print("Could not open {} for writing. error=\"{}\"\n", cgroup_path + "/cgroup.procs", strerror(errno));
+  }
+  output.write("0\n", 2);
+}
+
 /// Moves processes from source cgroup to destination cgroup.
 static bool move_procs_between_cgroups(const std::string& dst_path, const std::string& src_path)
 {
+  using namespace std::chrono_literals;
+
   std::ifstream source_file(src_path);
   if (source_file.fail()) {
     fmt::print("Could not open {} directory. error=\"{}\"\n", src_path, strerror(errno));
@@ -44,6 +56,8 @@ static bool move_procs_between_cgroups(const std::string& dst_path, const std::s
     }
     destination_file << std::stoi(pid) << "\n";
   }
+  std::this_thread::sleep_for(50ms);
+
   return true;
 }
 
@@ -56,6 +70,9 @@ bool configure_cgroups(const std::string& isol_cpus, const std::string& os_cpus)
     return false;
   }
 
+  /// First move itself to root cgroup.
+  move_to_cgroup(cgroup_path);
+
   /// Create cgroup for OS tasks, call it 'housekeeping' cgroup.
   if (!os_cpus.empty()) {
     std::string housekeeping = cgroup_path + "/housekeeping";
@@ -101,17 +118,9 @@ bool configure_cgroups(const std::string& isol_cpus, const std::string& os_cpus)
   if (!exec_system_command(set_cpus_cmd, isol_cgroup_path)) {
     return false;
   }
-  std::string set_partition_cmd = "echo root > " + isol_cgroup_path + "/cpuset.cpus.partition";
-  if (!exec_system_command(set_partition_cmd, isol_cgroup_path)) {
-    return false;
-  }
 
-  /// Writing the value 0 to a cgroup.procs file causes the writing process to be moved to the corresponding cgroup.
-  std::ofstream output(isol_cgroup_path + "/cgroup.procs");
-  if (output.fail()) {
-    fmt::print("Could not open {} for writing. error=\"{}\"\n", isol_cgroup_path + "/cgroup.procs", strerror(errno));
-  }
-  output.write("0\n", 2);
+  /// Finally move itself to isolcated cgroup.
+  move_to_cgroup(isol_cgroup_path);
 
   return true;
 }